If you create a scroll view with twice the content size of your view controller vertically like so, I did this in my view controller:
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:self.view.bounds];
scrollView.contentSize = GCSizeMake(self.view.frame.size.width, self.view.frame.size.height * 2);
You can then add your chart to the first page of your scroll view like so:
// Init chart here.
myChart.frame = CGRectMake(0, 0, scrollView.contentSize.width, scrollView.contentSize.height/2);
Now you can set your legend's frame so it is on the other page of your scroll view, I did this just after I initialised my chart:
[myChart.legend setFrame:CGRectMake(0, scrollView.contentSize.height/2, scrollView.contentSize.width, scrollView.contentSize.height/2)];
As our chart's legend is now outside of our chart's bounds, we need to tell it not to clip to bounds like so:
myChart.clipsToBounds = NO;
That should put your chart's legend on a seperate scroll view page to your chart. Of course, you will need to play with everything's autoresizing masks & frames to get it looking perfect .